Topic: 1962 Johnson Fisherman (5.5) fuel pump? – Antique Outboard Motor Club,Inc

This topic has 8 replies, 4 voices, and was last updated 8 years, 9 months ago by Mumbles.

Viewing 9 posts - 1 through 9 (of 9 total)

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July 14, 2016 at 2:31 pm #4751
amuller
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The official line is that these pumps are unrepairable and one should buy a new one. I’ve had one open and it doesn’t seem obviously more complex or tricky than other small OB pumps. Some parts breakdowns do show numbers for the two diaphragms (304092 and 379619)

http://www.vintageboatparts.com/shop/images/z/b012.jpg

Has anybody found a source for these, or made them successfully?

Thanks.
July 14, 2016 at 4:44 pm #40188
frankr
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OMC quit making parts for that pump over 40 years ago. I have replaced the diaphragm with a more recent kit and have my instructions "somewhere". I’ll post it if I can find it.
July 14, 2016 at 5:08 pm #40189
crosbyman
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Canada Member
worse case scenario I guess you could tap and nipple the pulse port then install a nice cheap Briggs Straton round pump for 15-12$

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July 14, 2016 at 5:44 pm #40192
frankr
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OK, I put the instructions in such a safe place I can’t find them. But the gist of it is as follows:

1. Use an OMC kit # 393103 (Sierra 18-7820. The only parts you will be using from it are the diaphragm and diaphragm support.

2. Take the pump apart ONLY at the seam closest to the engine. If you take the rest of it apart, you will find yourself needing obsolete gasket that is extremely difficult to make

3. The new diaphragm will "almost" fit, You will have to adjust the lower holes upward about 1/2 hole diameter.

4. Use the large diaphragm support from the kit. No promises from me as to the reliability of it. I worry it may slide out of position. The original support was riveted in place (??)

5. From here you are on your own.

6. Or just buy a new Sierra 18-7351 pump and go with it.
July 14, 2016 at 6:06 pm #40198
amuller
Participant
Thanks. I can do that.

I’ve also wondered if the #18-7334 (Yamaha) pump could work. It looks similar and is only about $25 on Amazon, but I don’t know about the mounting screw spacing.

http://cdn.overtons.com/product/900/900566_L1.jpg?
July 14, 2016 at 6:27 pm #40200
amuller
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quote crosbyman:

worse case scenario I guess you could tap and nipple the pulse port then install a nice cheap Briggs Straton round pump for 15-120$

Those round plastic pumps are cheap on ebay: $5-6, both the molded together ones and the ones with four screws. Tempting.
July 14, 2016 at 7:26 pm #40203
frankr
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Sure,it can be done. Here is one I put on a 12hp just to see how well it would work. One thing I had to do was fabricate a mounting bracket to hold the pump. Note the factory pump mount holes on the bypass cover. It would have been so.o.o.o.o much easier to just slap on the correct part.

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July 14, 2016 at 7:51 pm #40205
crosbyman
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Canada Member
added one (B&S) on my mid 50s 5.5. …works great but I agree…. a regular pump is easier .

p.s. meant 15-20$ not…$120 !!

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July 15, 2016 at 3:50 pm #40254
Mumbles
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If you want to cut your own diaphragm, you can buy a piece of Nitrile material here. A sheet is big enough to do several pumps.

http://www.pfs-ware.com/Parts/OllieParts.htm
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1962 Johnson Fisherman (5.5) fuel pump?

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